
.select-box{
  width: 1200px;
  height: 800px;
  margin: 0 auto;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 30px;
  font-weight: 500;
  color: orange;
  background: url("../images/background.jpg") no-repeat;
  background-size:  auto 800px;
  border: orange solid 2px;
}

#page-wrapper {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

#title {
  color: #f6f6f6;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 2em;
}

#btn {
  position: absolute;
  z-index: 5;
  top: 15px;
  left: 15px;
  cursor: pointer;
  transition: left 500ms cubic-bezier(0.6, 0.05, 0.28, 0.91);
}
#btn div {
  width: 35px;
  height: 2px;
  margin-bottom: 8px;
  background-color: white;
  transition: transform 500ms cubic-bezier(0.6, 0.05, 0.28, 0.91), opacity 500ms, background-color 250ms;
}

#btn.active {
  left: 230px;
}
#btn.active div {
  background-color: white;
}
#btn.active #top {
  transform: translateY(10px) rotate(-135deg);
}
#btn.active #middle {
  opacity: 0;
  transform: rotate(135deg);
}
#btn.active #bottom {
  transform: translateY(-10px) rotate(-45deg);
}

#box {
  position: absolute;
  z-index: 4;
  overflow: auto;
  top: 0px;
  left: 0px;
  width: 275px;
  opacity: 0;
  height: 100%;
  background-color: orange;
  color: white;
  transition:all 350ms cubic-bezier(0.6, 0.05, 0.28, 0.91);
}

#box.active {
  left: 0px;
  opacity: 1;
}

#items {
  position: relative;
  top: 50%;
  transform: translateY(-50%);
}
.item a,.item a:active,.item a:hover,.item a:link {
  text-decoration: none;
  color: white;
}
#items .item {
  position: relative;
  cursor: pointer;
  font-size: 40px;
  padding: 15px 30px;
  transition: all 250ms;
}
#items .item:hover {
  padding: 15px 45px;
  background-color: rgba(52, 56, 56, 0.2);
}

#btn,
#btn * {
  will-change: transform;
}

#box {
  will-change: transform, opacity;
}
